JP2020527494A - Methods for obtaining consolidation substances and the consolidation substances obtained thereby - Google Patents

Abstract

The present invention relates to a method for obtaining a compacted material as follows: a) A set of particles of a crude material is mixed with 1% to 50% by weight of a water-hard binder to form a dry composition. The percentage is based on the total weight of the dry composition, and the particle size distribution of the crude material particles is a first reference diameter d90 of 50 mm or less, and a second reference diameter of 0.08 micrometer or more. It is characterized by a reference diameter d10 and b) the dry composition formed in step a) is mixed with 1% to 35% by weight of water to form a mixed composition, the percentage of which is dry. For the total weight of the composition, c) the mixed composition from step b) was vibrated at a frequency of 20-80 hertz and an amplitude of at least 0.3 millimeters, during which time it was mixed. A compressive stress is applied to the composition, and the value of the applied compressive stress is at least 2 megapascals. The present invention also relates to a method for obtaining a multi-layer consolidation material and a material obtained by the method. [Selection diagram] Fig. 1

Description

The present invention generally relates to the field of consolidated materials.

More specifically, the present invention relates to a process for obtaining a consolidated material.

The present invention also relates to the consolidation material obtained in the process.

Many industrial processes use raw materials in the form of natural blocks, but their size is the industrial process they are intended for and / or the source of the crude material. Or it depends on the place of origin. In general, those blocks have typical dimensions between a few centimeters, for example 5 centimeters to 20 centimeters.

These blocks undergo operations such as mining, handling, transporting, weighing, and transporting them, in particular, before they are used in the industrial process they are intended for. In all of these operations, impacts and frictions occur, which produce dust or fine particles of crude material (commonly referred to as "fines"), which form the block. Not desirable in the industrial process used. Therefore, it is known that fine particles of these crude raw materials can be recovered by producing consolidated substances (also called agglomerates or briquettes regardless of the actual shape of the consolidated substances). , Can be used in industrial processes that normally use natural blocks.

Specifically, a process of producing a compacted substance from a mixture containing fine particles of a crude raw material and a Portland cement type hydrobic binder or molasse using a roller compressor. Is known. However, the consolidation material obtained from this process produces volatile organic compounds when used in industrial processes at high temperatures, especially above 500 ° C. In addition, this compacted material tends to crumble, resulting in so-called "secondary" microparticles. Finally, if the coarse particles of the crude material used to form the consolidation material (eg bauxite particles) are too hard, the rotary machine will quickly become exhausted.

A process for producing a "building block" type material in a building block press from a mixture containing fine particles of the crude material and a Portland cement type water hard binder is also known. In this process, the mixture is placed under low compressive stresses on the order of 0.01 megapascals. The building blocks obtained from this process also generate unwanted "secondary" particles. Moreover, the building blocks thus obtained are not suitable for use in hot industrial processes.

For the purpose of remedying the drawbacks of the prior art as described above, the present invention proposes a process for obtaining a consolidated material, wherein the obtained compacted material has an improved mechanical compressive strength. It has less secondary microparticle generation and can be exposed to temperatures between 500 ° C and 1700 ° C.

More specifically, in the present invention, a process for obtaining a consolidated substance is proposed as follows:
a) On the one hand, a set of crude material particles whose particle size distribution is characterized by a first reference diameter d90 of 50 millimeters or less and a second reference diameter d10 of 0.08 micrometer or more, and on the other hand. , A dry composition is formed by mixing 1% to 50% of a water-hard binder based on the total mass of the dry composition.
b) The dry composition formed in step a) is mixed with 1% to 35% water at a mass based on the total mass of the dry composition to form a mixed composition.
c) The mixed composition obtained in step b) is first vibrated at a frequency between 20 hertz and 80 hertz and an amplitude of 0.3 mm or more, and then combined with that vibration. A compressive stress is applied to the mixed composition to apply compressive stress.
The value of the applied compressive stress is 2 megapascals or more.

Therefore, in the process of the present invention, in step c), the mechanical compressive strength of the composition is improved and powdered by combining the vibration of the composition with applying a high compressive stress to the composition. It is possible to form a compacted material with a reduced crumbling rate. Reducing the pulverization rate means suppressing the generation of secondary fine particles, or, synonymously, improving the wear resistance of the consolidated substance.

In the process of the present invention, in step a), it is possible to adjust the size of the crude material particles of the set of particles, as well as the properties of the water-hard binder used, and as a result, obtained by the industrial process. The mechanical performance of the consolidated material can be adjusted to the desired level. In particular, prior to step a), additional sieving and / or crushing operations may be performed in the process to adjust the particle size used and / or modify the particle size distribution of said particles. It is possible.

Unexpectedly, by combining the particle size characteristics of the crude material particles and the properties of the water-hard binder, and by applying a high frequency and compression to the composition, the compacted material is brought to room temperature. The mechanical compressive strength of the compacted material, both when handled in and when used at high temperatures (500 ° C or higher) including the phase transformation of the compacted material, especially in the industrial process of the compacted material. It is possible to improve both the above and suppress the generation of secondary fine particles.

The process according to the invention can further produce a consolidated material in the form of a single layer or several layers of homogeneous crude material. This compacted material has an initial compressive strength, i.e., resistance to compression hours after its formation, especially 24 hours after its formation.

Furthermore, the process in the present invention provides a consolidation material that does not release volatile organic compounds, so that the consolidation material can be used in industrial processes at high temperatures, eg, between 500 ° C and 1700 ° C. Is.

The non-limiting and advantageous features of the process in the present invention, in all combinations that are individually or industrially possible, are:
-The mixed composition obtained at the end of step b) is used to form a first layer of material.
In step p1) prior to step c), steps a) and b) are repeated to form at least one other mixed composition.
In step p2), the other mixed composition obtained in step p1) is placed on the first layer formed at the end of step b) and at least two of the mixed compositions are placed. A stack of two layers is formed, and in step c), the stack formed in step p2) is vibrated at a frequency between 20 hertz and 80 hertz and an amplitude of 0.3 mm or more. Then, in combination with the vibration, the compressive stress is applied to the stack;
− In step n1), a core of a crude raw material is provided, and the core has a mechanical strength of 0.1 megapascal (MPa) or more.
In step n2) performed prior to step c), the core is completely encapsulated in at least one of the mixed compositions obtained in step b) and / or step p1). ,
In step c), the assembly containing the at least one mixed composition and the enclosed core has a frequency between 20 Hz and 80 Hz and 0.3 mm or more. Vibrate with amplitude and then apply the compressive stress to the assembly in combination with the vibration;
− In step n1), a core of a crude raw material is provided, and the core has a mechanical strength of 0.1 megapascal (MPa) or more.
In step n2') performed prior to step c), the core is mixed in and / or the other mixture obtained in step p1) in the mixed composition obtained in step b). Completely encapsulated in at least one of the compositions
In step c), the assembly containing the at least one mixed composition and the enclosed core is vibrated at a frequency between 20 Hz and 80 Hz and an amplitude of 0.3 mm or more. And then apply the compressive stress to the assembly in combination with the vibration;
-The core is a consolidation material formed by consolidation of other crude material particle sets;
-The core is obtained by the process of the present invention.

The present invention also relates to a process for obtaining a multilayer compacted material according to the following:
The first layer is made according to the following steps:
a) On the one hand, a set of crude material particles whose particle size distribution is characterized by a first reference diameter d90 of 50 millimeters or less and a second reference diameter d10 of 0.08 micrometer or more, and on the other hand. , A dry composition is formed by mixing 1% to 50% of a water-hard binder with a mass based on the total mass of the dry composition.
b) The dry composition formed in step a) is mixed with 1% to 35% water at a mass based on the total mass of the dry composition to form a mixed composition.
c) The mixed composition obtained in step b) is vibrated at a frequency between 20 hertz and 80 hertz and an amplitude of 0.3 millimeters or more, and then combined with the vibration to be mixed. Apply compressive stress to the composition
Then, in each subsequent layer, another mixed composition is prepared by repeating steps a) and b), but the other mixed composition is placed on the previous layer. The assembly formed by the previous layer and the other mixed composition is vibrated and compressive stress is applied to the assembly.
The value of the compressive stress applied is at least 2 megapascals to make at least the final layer of the multilayer consolidation material.

Thus, this other process allows the multi-layer consolidation material to be produced in the form of a stack of layers stacked on top of each other, but the layers of these crude materials are agglomerated with each other.

Other atypical and advantageous features of the process in the present invention, in all combinations individually or industrially possible, are:
-In each layer, the vibrations applied in combination with the application of compressive stresses should be anharmonic;
-In each layer, the vibration has an amplitude between 0.3 mm and 5 mm, depending on the direction of compression;
− In order to obtain the consolidated material, a step following step c) is further provided, in which the consolidated material is placed in a drying oven at a relative humidity above a predetermined temperature and relative humidity threshold. And leave for at least 24 hours;
-In each layer, the set of particles, or the crude material particles of each set of particles, are mineral particles selected from: red bauxite, white bauxite, alumina, limestone, lime, carbon, Carbon graphite, carbon black, rock wool, glass wool, carbonates, metallurgical eluents, manganese powder or derivatives thereof, metal ores or mixtures of ores (even those obtained during mining or manufacturing processes) Good), especially metal oxides or iron ore;
-In at least one layer or set of crude material particles, the first reference diameter d90 associated with the particle size distribution of the set of crude material particles is less than 20 millimeters and is associated with said particle size distribution. The second reference diameter d10 is greater than or equal to 0.1 micrometer;
-In each layer, the water-hard binder is selected from the following: Portland cement, calcium aluminates cement, sulfoluminate cement, cement mixed with fly ash, cement mixed with blast furnace slag, pozzolan and Mixed cement, or a mixture of the latter;
-In at least one layer, or at least one step a), the water-hard binder comprises calcium aluminates cement having a C / A molar ratio between 0.1 and 3;
− In at least one layer, or at least one step a), the water-hard binder has a particle size distribution of 100 micrometers or less, characterized by a first reference diameter d90. Consists of water-hard binder particles.

Finally, the present invention proposes a consolidation material, including particles of a crude material agglomerated with a water-hard binder, obtained by one of the processes of the present invention.

It is advantageous that the substance in the present invention has a mechanical compressive strength of 3 megapascals or more and a pulverization rate of 15% or less.

When the compacted material contains at least two layers of crude material that are both agglomerated, the layers of crude material are inactive with each other up to a predetermined threshold temperature.

Specifically, in a multi-layer consolidation material containing a stack of at least two layers, the layers of the crude material are inactive with each other until the temperature rises to a predetermined threshold temperature.

In a multi-layer consolidation material containing a core encapsulated in at least one outer layer, the crude material of the core is the crude material of the outer layer of at least one layer in which it is encapsulated. On the other hand, it is inactive until it reaches a predetermined threshold temperature.

Advantageously, the multi-layer consolidation material can be used in industrial processes that require the input of at least two types of crude material. Because it has multiple layers, the multi-layer consolidation material will have a chemical composition close to that desired for the product, especially in the final stages of the industrial process in which the multi-layer consolidation material is used. Can be. Therefore, in addition to the advantages already mentioned for single-layer compaction materials, multi-layer compaction materials can improve the controllability of chemical reactions within industrial processes, thereby resulting in low quality or specifications. The production of external products is suppressed, while certain classical phenomena when using the two crude materials, such as the adhesion of the crude materials to each other, are avoided. Furthermore, multi-layer consolidation makes it possible to optimize energy consumption in the industrial processes in which they are used, and even to improve productivity. The multi-layer consolidation material can also, in some cases, reduce wear and tear on the equipment in which it is used.

The following description, which gives a non-limiting example, will clarify what the invention is composed of and how to achieve it, together with the accompanying drawings.

Red bauxite fine particles In the figure showing an example of the cumulative particle size distribution of two batches L1 and L2, the y-axis is a fine particle having a diameter equal to or smaller than the size shown on the x-axis of the target batch. , Represents a cumulative percentage relative to the total mass of a set of fine particles in that batch. A batch of fine particles of red bauxite (called "ELMIN"), a batch of fine particles of white bokisite (called "ABP"), a batch of fine particles of Ciment Fondu (registered trademark) cement, and a batch of fine particles of Secar (registered trademark) 51 cement. In the figure showing an example of the particle size distribution of the batch, the y-axis is based on the total volume of the set of fine particles of this batch of red bauxite particles having the same dimensions as shown on the x-axis. , Represents a percentage of volume.

The present invention is to use the fine particles of the crude material in both an industrial process that requires the input of the crude material in the form of a block and an industrial process that applies a particularly high temperature of 500 ° C. or higher to the compacted material. It relates to a process for obtaining a compacted material of a crude raw material so that it can be recycled.

More specifically, the process in the present invention includes the following steps:
a) On the one hand, its particle size distribution is characterized by a first reference diameter d90 of 50 millimeters or less and a second reference diameter d10 of 0.08 micrometers or more, i.e. defined by the crude material. A dry composition is formed by mixing a set of material particles and, on the other hand, 1% to 50% of the water-hard binder by mass relative to the total mass of the dry composition.
b) The dry composition formed in step a) is mixed with 1% to 35% water at a mass based on the total mass of the dry composition to form a mixed composition.
c) The mixed composition obtained in step b) is first vibrated at a frequency between 20 hertz and 80 hertz and an amplitude of 0.3 mm or more, and then combined with that vibration. A compressive stress is applied to the mixed composition to apply compressive stress.
The value of the applied compressive stress is 2 megapascals (MPa) or more.

The rest of the description describes each process step in more detail.

Step a)
In step a), the set of crude material particles includes crude material particles selected from inorganic or organic crude material particles. It would be preferable to select the inorganic crude material particles. They may be naturally occurring inorganics, i.e. crude raw materials called "minerals", or synthetically derived inorganics.

In general, all crude raw material particles that are compatible with the water-hard binder, i.e. do not react with the water-hard binder, can be used in step a).

The set of crude material particles includes, for example, particles of crude material selected from the list of crude materials below: red bauxite, white bauxite, alumina, limestone, lime, carbon, especially carbon graphite and carbon. Black, rock wool, glass wool, carbonates, or metallurgical eluates, especially slag-type metallurgical eluates.

The set of raw material particles may further include particles of crude material selected from the following: manganese powder or derivatives thereof, metal ores or mixtures of ores, which are used during mining. , Or may be obtained in the manufacturing process), especially metal oxides or iron ores.

The crude material is preferably selected from the list below: red bauxite, white bauxite, alumina, limestone, lime, and carbon black.

It is more preferred that the crude material is selected from the list below: red bauxite, white bauxite, alumina, and limestone.

The set of raw material particles includes one or more different types of crude material, eg, those having different physicochemical properties. Thus, the set of raw material particles can include either a single type of crude material or a mixture of several different crude materials.

In step a), it is preferred that the set of raw material particles comprises a single type of crude raw material particles.

In the rest of the description, the crude material particles are sometimes referred to as "fine particles" because their diameters are blocks of natural crude material and consolidation obtained according to this process. This is because it is clearly smaller than any of the major dimensions of the chemical.

The "diameter" of a particle is defined herein as the maximum size of the particle, regardless of its shape.

Each particle in a set of source material particles has its own diameter, so that set of particles is its particle size distribution (also called "particle size"), i.e. its particle set. It is characterized, or defined by the statistical distribution of particle size (or diameter) of. The particle size distribution can be expressed as the volume, mass, or number of particles, if desired. In the rest of the description, the particle size distribution is always expressed in mass, with the exception of FIG. 2, which is expressed in volume. The particle size distribution in terms of volume is equivalent to the particle size distribution in terms of mass, and the density factor of the crude material correlates these two types of particle size distribution.

It would be more preferable if the reference diameters d90, d10, and d50 of the particle size distribution of the particles of the various sets could be defined, but the reference diameter quantitatively represents the statistical distribution of the size of the particles of the set. ..

Therefore, the first reference diameter d90, which represents the particle size distribution of the particle set, has 90% of the mass of the used fine particles based on the total mass of the fine particle set below the diameter. It is defined as the diameter of the particle.

In other words, the particle size distribution is characterized by a value of a first reference diameter d90, i.e. in the defined set of particles, relative to the total mass of the particle set of the particles in the set. 90% by mass has a diameter smaller than this predetermined first reference diameter d90, and 10% by mass of the fine particles of the set relative to the total mass of the particle set. , Has a diameter greater than this predetermined first reference diameter d90.

In other words, the particles of the particle set having a diameter smaller than the first reference diameter d90 occupy 90% of the total mass of the particle set when the particle size distribution is mass.

In this case, the first reference diameter d90 representing the particle size distribution of the set of fine particles of the crude raw material mixed in step a) is 50 mm (mm) or less, preferably 20 mm (mm) or less. Will be selected. Its first reference diameter is preferably between 15 millimeters (mm) and 100 micrometers (μm), more preferably between 10 millimeters (mm) and 500 micrometers (μm), and even 5 millimeters (mm). Will be between ~ 1 millimeter (mm). The first reference diameter d90 could also be chosen to be much smaller than that shown above, eg, less than 1 micrometer. In particular, the first reference diameter d90 may be selected below the following values: 20 mm, 15 mm, 10 mm, 5 mm; 1 mm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 200 μm, 100 μm, 50 μm, 20 μm, 10 μm; 5 μm, 1 μm, 0.5 μm, 0.4 μm, 0.3 μm.

The second reference diameter d10, which represents the particle size distribution of the particle set, has 10% of the mass of the used fine particles based on the total mass of the fine particle set below the diameter. Defined as diameter.

In other words, the particle size distribution is characterized by a value of a second reference diameter d10, i.e. in the defined set of particles, relative to the total mass of the set of particles in the set. 10% by mass has a diameter smaller than this predetermined second reference diameter d10, and 90% by mass of the fine particles of the set relative to the total mass of the fine particle set. , Has a diameter greater than this predetermined second reference diameter d10.

In other words, the particles of the particle set having a diameter smaller than the second reference diameter d10 occupy 10% of the total mass of the particle set when the particle size distribution is mass.

The second reference diameter d10, which represents the particle size distribution of the set of microparticles of crude material mixed in step a), is therefore 0.08 micrometers (μm) or greater, preferably 0.1 micrometers (μm). ), But the second reference diameter d10 is, needless to say, always smaller than the first reference diameter d90. The second reference diameter d10 is between 1 micrometer (μm) and 5 millimeters (mm), preferably between 10 micrometers (μm) and 1 millimeter (mm), and even between 100 micrometers (μm) and 500. It would preferably be between micrometers (μm). Specifically, the second reference diameter d10 may be selected by the following numerical values or more: 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0. 7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 20 μm, 50 μm, 100 μm, 200 μm, 500 μm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm.

The median diameter d50, which represents the particle size distribution of the set of particles, is a mass below that, based on the total mass of the set of fine particles, and is the diameter at which 50% of the fine particles used are present. Thus, in a set of particles whose particle size distribution is characterized by a value of median diameter d50, i.e. defined, 50% by weight of the particles in the set have a diameter smaller than this given median diameter d50. And 50% by weight of the fine particles in the set have a diameter greater than this given median diameter d50.

The reference diameters d90, d10, and median d50, which represent the characteristics of the size distribution of the various sets of microparticles, i.e. define the size distribution, are obtained from a particle size curve representing the respective statistical size distribution of the microparticles in that set.

In practice, the diameters d90, d10, and d50 can be determined by various methods such as a precipitation method (X-ray absorption detection method) or a laser diffraction method (ISO 13320 standard).

In the context of the present invention, the size of the microparticles is measured according to ISO 13320 standards, for example, by laser diffraction using a Mastersizer 2000 laser particle size analyzer (commercialized by Malvern).

FIG. 1 shows an example of the cumulative size distribution of two batches (ie, sets) L1 and L2 of red bauxite microparticles. More specifically, in FIG. 1, the y-axis is a mass based on the total mass of a set of fine particles of the batch having a diameter equal to or less than the size indicated on the x-axis, and is in the target batch. Represents the cumulative percentage of fine particles in. This graph shows these two batches of red bauxite microparticles, with a first reference diameter d90 of about 8 mm, a second reference diameter d10 between about 0.5 mm and 0.315 mm, and a median diameter d50. Indicates that it is between 2 mm and 3.15 mm.

The particle size distribution of the particles can be monomodal, in which one diameter outperforms the other of the total diameters adopted by the particles in the set of particles. This means that one of the diameters is employed at a significantly higher percentage of the particles compared to the other adopted diameters.

In other cases, the particle size distribution may be multimodal, but this is because some of the diameters employed by the particles in the particle set have other diameters. Beyond, or within a narrow diameter range, it means that some diameters make up a higher percentage of the particles.

FIG. 2 shows an example of a bimodal particle size distribution for a batch of red bauxite particles known as "ELMIN". More specifically, in FIG. 2, the y-axis represents the percentage of red bauxite particles having a diameter equal to the dimensions indicated on the x-axis, relative to the total volume of the set of particles in the batch. There is.

On this curve, there are two peaks in the particle size distribution of the particle diameter of the ELMIN particle set, namely the peak of the first particle with a diameter of 400 micrometers (7% by mass of the particle), and about 2.5 in diameter. The peak of the second particle of the micrometer (0.8% by mass of the particle) can be seen.

In general, the difference between the first reference diameter d90 and the second reference diameter d10 reflects the spread of the particle size distribution. Therefore, the smaller the difference between the first and second reference diameters, d90 and d10, the "narrower" the particle size distribution, i.e., the narrower the range of particle diameters in the particle set. Alternatively, the diameter values are closer to each other. Conversely, the greater the difference between the first and second reference diameters, d90 and d10, the "wider" the particle size distribution, that is, the wider the particle set diameter of the particle set. The values of, or their diameters, may be far apart.

In the context of the present invention, the particle size distribution can be selected, either relatively wide or narrow, as desired. In particular, a set of crude material particles with a wide particle size distribution will result in better particle stacking, which will reduce the amount of water-hard binder required to produce the compacted material. Consolidation materials made from this set of particles will exhibit better mechanical compressive strength. On the other hand, its pulverization rate will be higher than that of consolidated materials made from particle sets with a narrower particle size distribution.

In particular, prior to step a), such as sieving and / or crushing and / or grinding and / or assembling differential particle sizes and / or addition of fillers. It is also possible to adjust the size of the particles used and to modify the particle size distribution of the particle set by performing additional operations.

The process in the present invention was intended to facilitate the recycling of microparticles of crude material, however, to reduce additional costs and to produce microparticles generated at various stages of handling blocks of crude material. It is also important to use it as much as possible.

Furthermore, it is also advantageous to dry the coarse particles of the crude raw material here by placing them in a drying oven at 110 ° C. for 24 hours prior to step a).

In step a) of the process in the present invention, the fine particles of the crude raw material previously dried here are mixed with a water-hard binder and optionally other dried additives to prepare a dry composition. To form.

Although the preliminary step of drying the crude raw material is an optional step, it is preferable in order to facilitate the implementation of the step b) of mixing the dry composition.

In the rest of the description, the term "hydraulic binder" is used to form a paste-like consistency material that can be mixed with water to solidify agglomerate particles with each other. It will refer to a suitable powder or mixture of powders. In other words, in the rest of the description, the term "water-hard binder" solidifies when mixed with water, even in the cold, without the need to add another reactive substance. It is used to refer to substances that solidify in air as well as in water.

The term "dry composition" refers to a dry substance, a mixture of substances having a residual moisture content of 15% or less, the residual moisture content of which is the total mass of a set of crude material particles. And the difference (also called mass loss) from the mass after drying in an oven at 110 ° C. for 24 hours is calculated, and the difference is evaluated by dividing by the total mass. In other words, the residual moisture is obtained according to the following equation:
[(Total mass)-(Mass after oven drying)] / (Total mass)

Therefore, here, the dry composition is a water-hard binder, fine particles of the crude raw material (the fine particles of the crude material do not necessarily have to be oven-dried), and optionally other additives. Will refer to a mixture of.

The water-mixed composition is a dry composition after the addition of water. After contact with water for some time, the water-hard binder (or a dry composition containing the water-hard binder) solidifies due to its hydration reaction with water. It is called "set".

Here, the water-hard binder is selected from the following: Portland cement, calcium aluminate cement, sulfoluminate cement, cement mixed with fly ash, cement mixed with blast furnace slag, cement mixed with pozzolan. , Or a mixture of the latter.

The water-hard binder is preferably a set of water-hard binder particles whose particle size distribution is preferably represented by a first reference diameter d90 of 100 micrometers or less.

A dry composition comprising a set of water hard binder and fine crude material particles may have a monomodal or multimodal particle size distribution, i.e. the set of water hard binder and crude material particles It may have a single dominant diameter, or it may have several dominant diameters.

It is preferable that the water-hard binder contains calcium aluminates cement, that is, calcium aluminates powder.

In fact, by using calcium aluminates cement in the process of the present invention, a consolidated substance with a reduced amount of secondary fine particles generated can be obtained, especially when used in an industrial process at a high temperature, that is, a temperature exceeding 500 ° C. It became possible.

The use of calcium aluminates cement in the process of the present invention also makes it possible to obtain a consolidation material whose decay temperature (also called melting temperature) can be predicted.

Calcium aluminate cement during the contained in it, and lime CaO (in cement manufacturers Notation "C"), and Al 2 _O 3 alumina ₍ "A" in the cement manufacturer notation) It can be identified by the molar ratio of, more commonly known as the C / A ratio (according to the cement manufacturer's notation).

As used herein, the calcium aluminates cement used has a C / A molar ratio between 0.1 and 3.

Examples of the water-hard binder include Cement Fondu (registered trademark) having a C / A ratio of 0.95 and SECAR (registered trademark) 51 cement having a C / A ratio of 0.71.

In this case, the dry composition contains 1% to 50% of a water-hard binder, more preferably 2.5% to 15% of a water-hard binder, based on the total mass of the dry composition. including.

In practice, the amount of water-hard binder added to the dry composition depends on the properties of the water-hard binder, the properties of the fine particles of the crude material, and their particle distribution, as well as the properties required as a consolidation material, especially It depends on the aspect of mechanical compression strength.

In general, increasing the water-hard binder content in the dry composition results in improved mechanical performance, but also increases cost. Therefore, a compromise needs to be found.

Furthermore, the applicant of the present application has noticed that increasing the content of the water-hard binder in the dry composition increases the mechanical strength to some extent, but when the water-hard binder becomes excessive, a compression operation is performed. It becomes incompatible and cost-effective.

In step a), it is also possible to add additives to the dry composition. In particular, if desired, the workability of the water-mixed composition (ie, in this case, the water-mixed composition has a viscosity that allows it to be introduced into the compression mold. Rheology modifiers, such as surfactants or superplasticizers (also referred to as "shear-thinning agents"), as well as sclerosis inhibitors, to better regulate (time). Alternatively, a curing accelerator can be added.

Further, with these additives, when the mixture between the crude material and the water-hard binder, in particular, the crude material and the binder do not have any specific affinity for each other. Also, it becomes possible to make it more homogeneous.

In particular, it is possible to add Defoam (registered trademark) (Peramin) or Vinapor (BASF) as a surfactant, Compac500 (registered trademark) (Peramin) as a high-performance water reducing agent, and lithium carbonate as a curing accelerator. Is.

For example, when rock wool is used as a crude material and Cement Fondu® is used as a water-hard binder, lithium carbonate dissolved in concentrated soda ash can be used as an additive. In practice, it would be possible to make a composition comprising the following, in particular with a mass relative to the total mass of the dry composition:
− 86.4% rock wool,
-12.9% Cement Fondu®,
-0.7% lithium carbonate (Li ₂ CO ₃ ).

The pH of the mixed water added to this dry composition is adjusted to 13 by adding a few drops of concentrated soda water. In practice, in this case, for 38 ml (mL) of mixed water, 3.8 ml (mL) of concentrated soda solution concentrated to 1 mol / L, 34.2 ml (mL) of water. Add to.

Since the process in the present invention aims at recycling fine particles of crude raw material, it is desired to use as few additives as possible for cost reasons. However, their use is not prohibited unless either the compression stage or the final properties of the material compacted at high temperatures (500 ° C. or higher) are adversely affected.

In practice, in step a), the coarse particles of the crude material may be weighed, a water hard binder, various additives may be added, and the aggregate may or may not be mixed by hand. You may. In order to facilitate mixing, it is preferable to use a mixer, for example a Perrier type mixer. Such a mixer can be set to rotate for 1 minute at a speed of 140 rpm, especially in the context of the present invention.

Step b)
During step b) of the process in the present invention, the dry composition obtained at the end of step a) is mixed with 1% to 35% water by mass based on the total mass of the dry composition.

The dry composition is mixed with preferably 3% to 15% water, more preferably 3% to 9% water by mass relative to the total mass of the dry composition.

In general, the water-hard binder is completely hydrated and the surface of the microparticles of the crude material is wetted and water is added in an amount sufficient to give a homogeneous water-mixed composition. To do. Too much water in the composition can cause problems with the water-mixed composition becoming too sticky and demolding at the end of step c) and / or cleaning the mold. May wake up. In addition, excess water can also result in dehydration during the compression phase of the composition, which can lead to brittleness in the final compacted material, said brittleness. It is caused by the drainage of water through a convenient route. If the amount of mixed water is insufficient, this causes a pulverization phenomenon on the surface of the finally obtained consolidated substance, that is, secondary fine particles are generated on the surface of the consolidated substance.

In practice, in step b), the mixed water is added to the dry composition and mixed. In particular, the composition can be mixed in a Perrier type mixer, for example, at a rate of 140 rpm for 1 minute.

Water is added simultaneously or sequentially to several different locations of the composition to facilitate humidification of the composition and homogenization of the mixture.

Step c)
The water-mixed composition thus obtained at the end of step b) is then subjected to vibration.

For this purpose, the water-mixed composition is introduced into a rigid, eg steel mold, having a shape corresponding to the desired final form of the consolidation material. For example, the mold may have the shape of a cylinder or parallelepiped, with typical dimensions equal to about 10 centimeters, especially 20 centimeters.

Once filled, the mold is vibrated, for example by placing it on a shaking table or by various other vibrating means. The term "filled" means, as used herein, that the internal volume of the mold is at least partially occupied by the mixed composition.

The vibration reduces the amount of air trapped inside the water-mixed composition introduced into the mold.

In addition, if there is a bias in the mixing step and / or filling step into the mold, vibration will help to homogenize the microparticles of the crude material in the mold. In other words, vibration helps to homogenize the dispersion of particles in the mold.

The vibration has a frequency between 20 hertz (Hz) and 80 hertz (Hz), preferably between 25 Hz and 75 Hz. This frequency range fits well with the viscosity of the composition introduced into the mold. For example, the vibration has a frequency of 20 Hz, 25 Hz, 30 Hz, 35 Hz, 40 Hz, 45 Hz, 50 Hz, 55 Hz, 60 Hz, 65 Hz, 70 Hz, 75 Hz, or 80 Hz.

It is advantageous that the vibration has an amplitude between 0.3 mm (mm) and 5 mm (mm). In particular, the amplitude of the vibration is 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm. , 3.5 mm, 4 mm, 4.5 mm, or 5 mm. The amplitude of vibration in this case corresponds to the maximum moving distance of the mold in a predetermined direction. This amplitude range also fits well with the viscosity of the composition introduced into the mold. In other words, the amplitude represents the difference in position between the two extremes of mold movement.

The composition introduced into the mold is vibrated for a time between 2.5 and 15 seconds.

Then, at the same time as applying vibration, compressive stress is applied to the composition.

As a result, the vibration of the composition is carried out not only before the compressive stress is applied, but also while the compressive stress is applied.

When compressing the composition, it is advantageous to vibrate in the direction of the compression. In other words, the mold reciprocates in the direction of compression.

So, for example, if the compression is generally vertical, then the type is a number, i.e. a distance equal to the amplitude of the vibration, at a predetermined frequency, i.e. a frequency equal to the frequency of the vibration. Move up and down millimeters.

It is advantageous that the applied vibrations are anharmonic while the compressive stress is applied. In other words, the vibration has an anharmonic profile. In this case, the term "anharmonic" means that the frequency and amplitude of the vibration is not constant over time, that is, the anharmonic vibration is aperiodic (the vibration has periodicity). Does not mean). Conversely, a "harmonic" vibration consists of one or more frequencies and amplitudes that remain constant over time, i.e., a harmonic vibration is periodic. In other words, the frequencies and amplitudes of the applied anharmonic vibrations are not regular over time, i.e. they are regularly repeated during the implementation of step c). Take no value.

In practice, for example, at least one type of shock can deliberately disturb the vibrations, causing them to be irregular (ie, aperiodic). Therefore, the mold is not only moved regularly, i.e. periodically, in the direction of compression, but it is also subject to at least one type of short, high-intensity disturbance to disturb the vibrational harmony. There is. Therefore, the anharmonic vibration has a profile corresponding to the sum of the sinusoidal profile and the disturbance.

For example, it is possible to create a vibration by rotating at least one type of anharmonic exciter attached to the shaking table, and this vibration is caused by at least one type of impactor hitting the shaking table. To be out of harmony. Using a movable wedge inserted between the unbalanced exciter and the plate of the shaking table, the rotation of the unbalanced exciter impacts the wedge, thereby creating a promotion of vibration anharmonicity. It is also possible.

In practice, in combination with the application of compression, the specificity applied preferentially to the vibration, in particular the direction of the vibration and the anharmonicity of the vibration, to the vibration performed before the application of compression. May also be applied.

As mentioned earlier, in the process of the present invention, a high compressive stress is applied to the composition in combination with vibration.

"Compressive stress" is defined as the compressive force divided by the surface area to which the force is applied, but the surface is perpendicular to the compressive force, i.e. the direction of the compressive force. ..

In this case, the compressive stress applied to the composition is 2 megapascals (MPa) or more. Specifically, the compressive stress can be between 2 megapascals (MPa) and 5 megapascals (MPa). It may be selected at 10 megapascals (MPa) or higher. For example, it is 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa, 50 MPa, 55 MPa, 60 MPa, It is selected equally to 65 MPa and 70 MPa. This high compressive stress keeps the coarse particles of the crude material in close contact with each other at the onset of curing of the water-hard binder, thereby ensuring high cohesiveness between the particles.

In fact, the higher the compressive stress applied to the material, the stronger the consolidation of the crude material particles with each other, and the more forcibly inserted the water-hard binder between the particles. Therefore, the aggregation of the consolidated substance, that is, its high mechanical compressive strength and low pulverizability is ensured.

In practice, the compressive force is applied homogeneously to one side of the mixed composition introduced into the mold. For example, compressive force is applied by means of a plunger of the same size as the surface of one side of the mold.

In general, step c) is carried out in a sufficiently short time so that the composition does not have enough time to cure in the mold. In other words, the water-mixed composition is self-sustaining due to the application of vibration and compressive stresses, without the water-hard binder actually initiating a reaction with water. (Stand by itself), thereby the consolidation material obtained at the end of step c) can be demolded without deformation, but without initiating hardening. At the end of step c), the composition is firm enough to allow demolding and delicate handling.

After step c), the consolidation material is removed from the mold. After demolding, the compacted material begins to cure, i.e., water hydrates the water-hard binder and actually solidifies. During this solidification process, its mechanical strength develops.

Advantageously, it is preferable to carry out a step of placing the consolidated substance in a drying oven in a predetermined temperature and moisture controlled atmosphere, following the demolding of the consolidated substance. It is during this oven-drying process that the water-hard binder "sets", thereby solidifying the compacted material.

In general, the oven-drying process results in the aging of the consolidated material, i.e. solidifying the material, which is mechanically strong according to a phenomenon commonly referred to as "structuring". Start acquiring. When alumina cement is used, curing occurs 2-3 hours after the compression step, preferably during the oven drying step. This oven drying process affects the microscopic structure of the consolidation material.

In practice, the oven drying conditions depend on the water-hard binder used. In particular, oven drying is performed for a predetermined time, at a predetermined temperature, and at a relative humidity above a relative humidity threshold.

In this case, it is selected to place the consolidation material in a drying oven for 24 hours.

The relative humidity threshold is selected according to the water-hard binder used.

For example, if the water-hard binder used is calcium aluminates cement, the compacted material is placed in a drying oven at a relative humidity of 80% or higher for at least 24 hours.

The relative humidity of the air contained in the drying oven (also called humidity of humidity) is the saturated vapor pressure (vapor pressure) of the partial pressure of the water vapor contained in the air at the same temperature. Or it is defined as the ratio to vapor tension). In other words, relative humidity represents the ratio between the water vapor content of the air in the drying oven and the maximum volume of this air containing water under predetermined temperature conditions.

The mechanical properties of the surface of the consolidation material are extremely important in limiting the formation of secondary particulates. In order to minimize the formation of secondary microparticles, the water-hard binder must be as completely hydrated as possible. In some cases, the mixed water added in step b) prior to the application of vibration and compressive stresses in step c) is not sufficient to completely hydrate the dry composition, especially the water-hard binder. is there. For this purpose, the relative humidity during oven drying is preferably above 90% of the first preset threshold and even above 95% of the second preset threshold. There must be.

In addition, the oven drying temperature is also crucial for the final microscopic structure of the compacted material and depends on the water-hard binder used.

In practice, if the water-hard binder used is calcium aluminates cement, oven drying is performed at a temperature between 10 ° C and 28 ° C. Priority is given to oven drying at temperatures between 15 ° C. and 25 ° C., even between 18 ° C. and 20 ° C.

When using other water-hard binders such as Portland cement or calcium aluminates sulfate, higher oven drying temperatures are desirable for mechanical strength.

When the water-hard binder used is preferentially calcium aluminate cement (C / A molar ratio is 1) containing calcium monoaluminate (CA) as the main crystal phase, it is formed by a hydration reaction. The hydrate to be produced depends on its hydration temperature. However, the higher the hydration temperature, the smaller the volume of hydrate formed, the less water molecules consumed by CA to form the hydrate, and the less hydrate formed. Contributes less to the development of mechanical strength of the compacted material. For this reason, the compacted material is at a temperature high enough to accelerate the hydration reaction and thus solidify the compacted material, while the hydrates formed become the compacted material. In contrast, it provides the desired properties and minimizes the conversion of these hydrates (ie, the chemical transfer of hydrates due to dehydration) obtained from calcium aluminate type water-hard binders. Should be oven dried at a temperature low enough to.

Therefore, if the consolidation of the consolidated material can be completed in the drying oven, the mechanical properties of the consolidated material will be improved.

Needless to say, as an alternative, it is also possible to leave in air air instead of oven drying to complete the cure.

The compacted material thus obtained forms a homogeneous layer of crude material agglomerated by the water-hard binder.

The consolidated material thus obtained is characterized by a mechanical compressive strength of 3 megapascals or more at 20 ° C.

In addition, it has a pulverization rate of less than 15%, preferably less than 10%. For example, the pulverization rate may be 15% or less, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5% or less.

Such a low pulverization rate ensures that the substance produces very little secondary fine particles. This means that its wear resistance is high.

The pulverization rate T, that is, the generation rate of secondary fine particles, is, on the one hand, the difference between the initial mass of the consolidation substance and the mass of the consolidation substance after pulverization, and on the other hand, the initial mass of the consolidation substance. Is the ratio of. The pulverization rate can also be expressed according to the following equation:
T = [initial mass-final mass] / initial mass

In the section of "Examples" below, how to actually measure the pulverization rate T will be described.

Advantageously, it is also possible to form a multi-layer consolidation material, i.e. containing at least two separate layers of crude material, according to the same principles described above for obtaining a single layer consolidation material. It is possible.

Such multi-layer consolidation materials include, in particular, stacks of layers superimposed on each other, or layers encapsulated within other layers, thereby at least one. It may include a core that is integrated and enclosed within the outer layer of the layer.

More specifically, a multi-layer consolidation material containing at least two layers of superposition on top of each other can be obtained by the process described above, but in summary:
The mixed composition obtained at the end of step b) is used to form a first layer of material.
In step p1) prior to step c), steps a) and b) are repeated to form at least one other mixed composition.
In step p2), the other mixed composition obtained in step p1) is placed on the first layer formed at the end of step b) and at least two of the mixed compositions are placed. A stack of two layers is formed, and in step c), the stack formed in step p2) is vibrated at a frequency between 20 hertz and 80 hertz and an amplitude of 0.3 mm or more. Then, in combination with the vibration, the compressive stress is applied to the stack.

Step p1) is the same as steps a) and b) described above in all respects.

In other words, in step p1), another dry composition has a first reference diameter d90 with a particle size distribution of 50 mm or less and a second reference diameter of 0.08 micrometer or more. Formed by mixing another set of raw material particles as defined by d10 and, on the other hand, another water-hard binder of 1% to 50% by mass relative to the total mass of the dry composition. Then, the other dry composition formed is mixed with 1% to 35% water by mass based on the total mass of the other dry composition, and the other mixed composition is mixed. To form.

The one obtained at the end of step b) and the one obtained at the end of step p1) are different, but it is preferable if they can be recognized as the same. The differences are specifically the essence of the crude material particles and / or their particle size distribution, and / or the essence of the water-hard binder used, and / or the amount of binder used, and / Or it may be due to the amount of water used to mix the dry composition.

Step p1) can be repeated as many times as necessary to form many identical or different mixed compositions as the desired stacked layers in the multilayer compacted material.

The first mixed composition obtained at the end of the first step b) is placed in a mold to form a first layer of material. The second mixed composition obtained at the end of step p1) is placed on top of this first layer to form a two-layer stack. By doing so, any number of mixed compositions can be superposed in the mold to form a corresponding number of layers in the multi-layer consolidation material.

Only after all the mixed compositions are stacked on top of each other in the mold, the process of obtaining a single layer material under the conditions described above (ie, at least one vibration between 20 Hz and 80 Hz). The mold is vibrated with a number and vibration with an amplitude of 0.3 mm or more), and then combined with the vibration, a compressive force of 2 megapascals or more is applied.

In other words, step c) described above is carried out on a stack of layers formed by superimposing the mixed compositions. Therefore, step c) is effectively applied to the first mixed composition contained in the stack.

Specifically, in this case, either the first layer formed by the first mixed composition, or any intermediate layer formed by the mixed composition added on top of each other. No vibrations or compressive forces are applied until the final mixed composition is placed on top of everything else. Only after the final mixed composition has been placed on top of the others forming the stack, is it vibrated and then vibrated under the conditions described above for the process for obtaining a single layer material. A compressive force is applied together with.

By doing so, it becomes possible to prepare a multi-layer consolidation material containing at least two stacked layers by a simple method.

Alternatively, at least its first layer, or said first layer and its first, prior to placing the final mixed composition on top of others to form the final stack. It is also possible to vibrate the intermediate stack formed by several intermediate layers deposited on the layer. The final mixed composition is placed on at least its first layer, or on top of said first layer and its first layer, before placing it on top of others to form the final stack. It is also possible to apply a compressive force to the intermediate stack formed by several precipitated intermediate layers.

By vibrating the intermediate stack, the particles can be interrelated and optimally aligned. By applying compressive stresses to the intermediate stack, even if low, it is possible to obtain regular layers after the final demolding. Therefore, the intermediate consolidation improves the aesthetic appearance of the final multi-layer consolidation material.

A multi-layer consolidation material containing a core encapsulated in at least one outer layer can be obtained by one of the processes described above, which can be summarized as follows:
In step n1), a core of a crude raw material is provided, and the core has a mechanical strength of 0.1 megapascal (MPa) or more.
At least one of the mixed compositions obtained in step b) and / or step p1) said core in step n2) or n2') prior to step c) of the process described above. Completely enclosed inside, and
In step c), the assembly containing the at least one mixed composition and the enclosed core is vibrated at a frequency between 20 Hz and 80 Hz and an amplitude of 0.3 mm or more. Then, in combination with the vibration, the compressive stress is applied to the aggregate.

In step n1), the core intended to form the inner layer of the final multi-layer consolidation material has mechanical strength, so it is possible to handle this core and move it. Become.

The mechanical strength in question here is the mechanical compressive strength (expressed in units of megapascals (MPa)) evaluated according to the protocol described in the EN 196 standard.

In step n1, the core may be a block of natural solid material such as bauxite or limestone.

It may be a synthetic solid material obtained by some consolidation process, for example by consolidation or granulation of natural or synthetically derived micromaterials.

In particular, the core can be obtained by a already known consolidation process.

Alternatively, the core may be a consolidation material obtained by one of the processes of the invention described above. In other words, the core may be a "single layer" compacted material obtained according to steps a), b) and c) described above, or as described above. It may be a multilayer material containing a stack of at least two layers obtained according to steps a), b), p1), p2) and c).

If the core is a consolidation material obtained by any type of consolidation process, then the core is of the particles used in step a) to obtain the desired composition for encapsulating the core. It preferably contains a set of crude material particles having properties similar to those of the set. Specifically, the particle size distribution and properties of other sets of crude material used to form the core will be the same as previously described in connection with step a). .. However, the properties of other sets of crude material particles used to form the core, especially the particle size distribution, of the set of particles used to form the composition for encapsulating the core. It does not have to be the same as the characteristics of the crude material particles, especially the particle size distribution.

In the final multi-layer consolidation material, it is preferable that the core and the compacted outer layer surrounding it are different. This difference may be due, for example, to the nature of the crude materials they contain and / or to the particle size distribution of their individual particle sets.

When the core is obtained according to one of the processes of the present invention described above, the amount, particle size distribution, and properties of the water-hard binder used to form the core are the core. The water-hard binder in its core, which is similar to that of the binder used in the composition of interest for encapsulation, may have the properties described above. Conversely, the properties, particle size distribution, and / or amount of the water-hard binder used to form the core used to form the mixed composition surrounding the core. It does not have to be the same as that of.

Regardless of the method of including the core in step n1), step n2) or n2'), the core is contained in at least one mixed composition obtained in step b) and / or step p1). It is completely enclosed. In other words, the mixed composition is placed under, around, and above the core to completely enclose the core in the mixed composition.

According to the first possibility, the core can therefore be completely encapsulated in one and the same mixed composition, for example as obtained in steps b) (step n2)). it can.

For this purpose, for example, the mixed composition obtained in step b) is placed on the bottom of a mold having dimensions (height and width) greater than the dimensions of its core, and then on top of that. Place the core that will form the "core" of the multi-layer compaction material, then use the mixed composition to fill the lateral space between the core and the mold and completely cover the core. ..

The core may be encapsulated in the mixed composition obtained at the end of step p1) of the process described above. In this case, the final multi-layer consolidation material obtained has a first layer and then a second layer in which the core is integrally encapsulated (step n2'). ing.

According to the second possibility, the core is encapsulated in two separate and different mixed compositions, whereby it is partially enclosed by the first mixed composition. And may also be partially enclosed by a second mixed composition. As a result, the core is confined at the interface between the two overlapping layers of the layer stack (a modified method of step n2').

For this purpose, for example, the mixed composition obtained in step b) is placed on the bottom of a mold having dimensions (height and width) greater than the dimensions of its core and the core is placed there. When placed, it then forms the "core" of the multi-layer compaction material, and the lateral space between the core and the mold is the height of the core using the same mixed composition. The side space between the core and the mold is then filled to half the height, for example with the second mixed composition obtained at the end of step p1), said second mixing. The core is completely covered with the prepared composition.

Step c) is the same as described above, except that in the case of a multilayer material having a core enclosed in at least one outer layer, vibration and then compressive stress are mixed with the vibration. It is applied to an assembly containing the composition and the enclosed core.

When compressive stress is applied to the mixed composition and the assembly containing the encapsulated core, the compressive stress is actually applied to the core, and this compressive stress is applied to the mixed composition. It will be. Therefore, step c) is actually performed on at least the first mixed composition.

Doing so results in a multi-layer consolidation material containing a core completely encapsulated in at least one outer layer.

Alternatively, the core used in step n1) is itself a multi-layer consolidation material encapsulated in a layer and containing another core, i.e., a multi-layer consolidation obtained according to the process described immediately before. It will be easy to understand that it can be a chemical substance.

The rest of what has been described in relation to the process for obtaining a single layer consolidation material is the multi-layer consolidation material obtained by one of the processes of the present invention (a stack of layers with layers on top of each other). It can also be applied to a multi-layer consolidation material containing, or a multi-layer consolidation material containing a layer encapsulated in at least one outer layer).

Multilayer consolidation materials, including stacks of layers stacked on top of each other, can also be obtained according to the process for obtaining the multi-layer consolidation material, according to which the first layer is produced according to the next step. :
a) On the one hand, a set of crude material particles whose particle size distribution is characterized by a first reference diameter d90 of 50 millimeters or less and a second reference diameter d10 of 0.08 micrometer or more, and on the other hand. , A dry composition is formed by mixing 1% to 50% of a water-hard binder based on the total mass of the dry composition.
b) The dry composition formed in step a) is mixed with 1% to 35% water at a mass based on the total mass of the dry composition to form a mixed composition.
c') The mixed composition obtained in step b) is vibrated at a frequency between 20 hertz and 80 hertz and an amplitude of 0.3 mm or more, and then combined with the vibration to form the mixture. Compressive stress is applied to the resulting composition.

Steps a) and b) of this process for obtaining a multi-layer consolidation material containing a layered stack are, in all respects, described above for the process for obtaining a single layer consolidation material, step a. ) And b) are similar.

Step c') is in all respects similar to step c) of the process for obtaining a single layer compacted material, except in step c'). The point is that it is not essential that the value of the applied compressive stress is 2 MPa or more. For example, it may be on the order of 0.1 MPa.

This first layer forms the bottom layer of the layer stack.

Then, in order to form the next layer, another mixed composition is prepared by repeating the steps a) and b) described above, and the other mixed composition is preliminarily applied. Place on top of the layer.

In practice, the other water-mixed composition obtained by repeating steps a) and b) above is directly added to the end of step c') for forming the first layer (hereinafter, the same applies). ..

In that way, the other mixed composition is placed on top of the already formed first layer in the same mold.

Other water-mixed compositions, in particular, fine particles of crude material whose properties differ from those of the set of raw material particles of the first layer and / or whose particle size distribution is different. It is preferably different from the first water-mixed composition used to form the first layer of material in that it contains a set of. The water-hard binder used in this other water-mixed composition may be the same or different, similar to the ratio of binder to crude material.

For example, the first layer is 85% red bauxite by mass relative to the total mass of the first dry composition (its particle size distribution is less than 20 millimeters, first reference diameter d90, and 0. It has a second reference diameter d10 of .08 micrometers or more), and can be formed from a first dry composition comprising 15% Cement Fondu® cement, and its first. Layer 2 is 95% limestone CaCO ₃ by mass relative to the total mass of the second dry composition (its particle size distribution is less than 20 millimeters, first reference diameter d90 and 0.08 micrometers. It has the second reference diameter d10 above), and it is imaginable that it is formed from a dry composition containing 5% Cement Fondu® cement.

It is then carried out that the second composition is mixed with water and the second composition thus mixed is introduced into a mold that already contains a first layer of material. To. The second composition may or may not be mixed with water in the same proportions as in the case of the first composition.

For example, in the example given above, the first dry composition is mixed with 7% water by mass relative to the total mass of the first dry composition, whereas the second dry composition Is mixed with 5% water by mass based on the total mass of the second dry composition.

An assembly formed by the previous layer (here, the first layer) and other mixed compositions covering it is then subjected to vibration and compressive stress is applied to the assembly. ..

As in the case of the formation of the first layer, the assembly consisting of the first layer and the mixed composition covering it is first vibrated and then vibrated into the assembly while maintaining the vibration. Apply compressive stress.

The application of vibration and compressive stresses is, in all respects, similar to that described in Forming the First Layer. In particular, in order to form the first layer, vibration is applied at a frequency between 20 Hz and 80 Hz and an amplitude of 0.3 mm or more, whereas the compressive stress is 2 MPa or more. do not have to.

Therefore, step c') is performed on the aggregate formed by the first layer and the second layer.

By vibrating the aggregate formed by the first layer and the second layer, the particles can be interrelated and optimally aligned.

By applying compressive stresses to this assembly, even if it is low, it is possible to obtain regular layers after the final demolding. Therefore, the intermediate consolidation improves the appearance of the final multi-layer consolidation material.

The same applies to the formation of each of the subsequent layers. In other words, in order to form each subsequent layer, steps a) and b) are repeated to obtain a new mixed composition and this new mixed composition is placed in a mold. Introduce on the previous layer of, and therefore, if necessary, on all previously formed layers. An assembly containing the previously formed layer and the newly mixed composition is vibrated and then combined with the vibration, compressive stress is applied to the assembly. More specifically, for each subsequent layer, step c') is performed on a new assembly containing the previously formed layer and the newly mixed composition.

At least, in order to form the last layer of the multi-layer consolidation material, that is, the uppermost layer of the stack, the value of the compressive stress applied must be 2 megapascals or more, for example, 10 megapascals or more. It is essential to obtain a chemical substance. Therefore, the step c) described above is carried out on the last layer of the stack, that is, the uppermost layer. It should be noted that applying a compressive stress of 2 MPa or more over the last layer effectively applies this compressive stress to all layers of the stack.

Therefore, if the compacted material is composed of only two layers, it is possible, but not necessary, to set the compressive stress value to 2 MPa or more when forming the first layer. , It is essential that the value of the compressive stress applied when forming the second layer is 2 MPa or more. The value of the compressive stress applied to form the second layer is preferably 5 MPa or more, or even 10 MPa or more.

Intermediate compressive stresses on the water-mixed composition that form either the first layer of the consolidated material or the intermediate layer of the consolidated material when producing a multi-layer consolidation material according to this process. However, it is preferably lower than the final compressive stress immediately before the multi-layer consolidation material is demolded. In particular, the compressive stress in the middle can be less than 2 megapascals. For example, it may be on the order of 0.1 megapascals.

In other words, for the purposes of carrying out the process of the present invention, all of the compressive stresses that the multi-layer consolidation material receives during multiple steps c) of the process for obtaining the multi-layer consolidation material. However, it does not have to be 2 MPa or more. On the contrary, in the process carried out in the present invention, it is sufficient if the compressive stress carried out in one of the plurality of steps c) of the process in the present invention is 2 MPa or more. The final compressive stress, which directly precedes the demolding of the multilayer consolidation material, is preferably 2 MPa or more, more preferably 5 MPa or more, and even more preferably 10 MPa or more.

By applying at least one very high compressive stress to the final layer of the multilayer material, all the layers will be tightly bound to each other and the microparticles will be properly agglomerated. However, if it is desired to further increase the compressive strength of the multilayer consolidation material, a compressive stress of 2 MPa or more may be applied when forming each layer.

It is preferred that all compressive stresses applied in different steps of the process be applied in the same compression direction.

Alternatively, compressive stresses applied in different process steps are applied in different compression directions.

The resulting multi-layer (two or more layers) consolidation material is then removed from the mold and then oven dried, if possible, according to the oven drying step described above.

Furthermore, it is also possible to combine a process for obtaining a multi-layer consolidation material containing a core enclosed in an outer layer and one of the processes for obtaining a multi-layer consolidation material containing a stack of layers. is there. By doing so, the core encapsulated in the first layer and at least one second layer overlaid on the aggregate containing the core encapsulated in the first layer. It is possible to produce a hybrid multi-layer compaction material having both.

Needless to say, by combining the various process steps described above, a hybrid multi-layer consolidation that includes both several cores encapsulated within several outer layers and several superposed layers. It is also possible to obtain chemical substances. It is essential that the compressive stress applied when forming the last layer is 2 MPa or more, but in the case of the mesosphere, this is not essential.

Regardless of the number of layers of the multilayer compacted material formed, it is advantageous that the layers of the crude material are mutually inactive until they reach a predetermined threshold temperature. In other words, the layers do not react with each other until the temperature reaches a predetermined threshold temperature, which is significantly higher than the ambient temperature. In other words, the crude material in one layer does not react with the crude material in the adjacent layer until a predetermined threshold temperature is reached. Specifically, they do not react with each other until they reach temperatures above 500 ° C. In other words, they do not react with each other until they reach temperatures above 400 ° C, above 300 ° C, above 200 ° C, or above 110 ° C. This applies to multi-layer consolidation materials with layer stacks, as well as multi-layer consolidation materials with cores encapsulated in outer layers, and hybrid multi-layer consolidation materials.

Specifically, in a multi-layer consolidation material containing at least one kind of core enclosed in at least one outer layer, the crude raw material of the core is outside until the temperature rises to a predetermined threshold temperature. It is inactive with respect to the crude material of the layer.

Regardless of the number of layers of the multi-layer consolidation material formed, the multi-layer consolidation material has a compressive strength of 3 megapascals or more, similar to a single-layer consolidation material. Therefore, the multi-layer consolidation material can be handled without decomposition.

Furthermore, in the multi-layer consolidation material, all layers in contact with the outside generate almost no secondary fine particles at least until the melting temperature of the multi-layer consolidation material is reached.

Therefore, in the case of a multi-layer consolidation material having a stacked layer, each layer of the multi-layer consolidation material hardly generates secondary fine particles until at least the melting temperature of the multi-layer consolidation material is reached. In the case of a multi-layer consolidation material containing a core encapsulated in the outer layer, the outer layer produces little secondary microparticles at least until the melting temperature of the multi-layer consolidation material is reached.

The melting temperature of the multi-layer consolidation material can be determined in advance by appropriately selecting the water-hard binder of the composition of each layer of the multi-layer consolidation material.

Preferably, in the case of a multi-layer consolidation material having a core encapsulated in at least one outer layer, the melting temperature of the multi-layer consolidation material is suitable for the water-hard binder of the composition of the outer layer. It can be decided in advance by selecting.

Thanks to the process in the present invention, it has become possible to produce multi-layer consolidation materials, particularly including layer stacks, cores encapsulated in outer layers, or a combination of their configurations. These multi-layer compacted materials are industrial processes that require the input of at least two types of crude materials, in particular alumina-rich crude materials (pure or partially hydrated) and lime-rich crude materials. It can be used in ore smelting processes that may require the use of blocks (pure or partially carbon oxides).

In practice, the multi-layer consolidation material can be designed so that the product obtained from the industrial process has a chemical composition close to that desired. By adjusting the composition of the multilayer materials, the regulation of chemical reactions is improved by homogenizing the chemical composition within the industrial process, especially in the ore melting furnaces. This limits the quality of deterioration and the production of non-standard products, while certain classical phenomena that occur when two crude materials are used in an industrial process, eg, crude materials. Mutual adhesion and advancement of a slop (especially in ore melting furnaces) are avoided.

The rest of the description provides examples of various compacted materials produced by the process of the present invention, as well as examples of those produced by other processes not according to the invention for comparison purposes. The consolidated material formed is then characterized by mechanical testing.

I. Manufacturing Equipment The consolidation material produced by the process of the present invention can be obtained in so-called "miniature" or "laboratory" equipment.

The miniature device includes a press commercially available from MEDELPHARM under the name Style'One Evolution, which is combined with a vibration generator. The Style'One press has two opposing punches, a lower punch and an upper punch. In this case, the upper punch is used to apply compressive stress by applying a force of up to 50 kilonewtons (kN). The lower punch is held in the stop position and connected to the vibration generator.

The vibration generator includes a rotating shaft, one end of which is connected to the lower punch and the other end carrying an unbalanced exciter, an object whose shape is asymmetric with respect to the rotating shaft. There is. The unbalanced exciter can be loaded between 3 and 16 grams and can rotate at speeds of 40 rpm (40 Hz) to 60 rpm (60 Hz). With this system, the amplitude of vibration is between 0.35 mm and 1.05 mm.

The water-mixed composition is introduced into a steel mold with a rectangular cross section measuring 23 mm wide x 31 mm long and centered on the axes of the two punches. Therefore, the compressive stress applied to the composition contained in the mold is 70 MPa at the maximum. In practice, in this case it will be adjusted to be equal to 11 MPa.

The production conditions for the substances to be consolidated in the miniature device are summarized in Table IA below.

The consolidated product thus obtained is manually demolded and then placed in a drying oven at 20 ° C. and 90% relative humidity for 24 hours.

The consolidation material produced by the process of the present invention can be obtained in so-called "pilot" devices.

The device includes a vibrating press as described in QUADRA's European Patent Application No. 1875996.

The facility includes a crude material mixing station mounted on top of a casting / molding station for compounding materials.

The water-mixed composition is prepared using a conical mixer. It is then introduced into a 4 cm thick steel mold with 30 briquette recesses capable of withstanding intense pressures up to 25 MPa. Place the mold under the punch. In this case, the compressive stress exerted on the composition contained in the mold will be between 1.5 and 25 MPa.

The production conditions for the materials to be consolidated in the pilot device are summarized in Table IB below.

The consolidated product thus obtained is manually demolded and then placed in a drying oven at 18 ° C. and 95% relative humidity for 24 hours.

II. Strength test and pulverization test Once the consolidated substances were obtained, they were subjected to mechanical tests to evaluate their mechanical compressive strength and their pulverization rate, but the latter generated more or less secondary fine particles. To reflect.

If the mechanical compressive strength is 3 MPa or more, the consolidated substance can be handled and transported without being destroyed. Therefore, it is considered satisfactory in the context of the present invention.

A low, i.e. 15% or less pulverization rate is synonymous with high abrasion resistance and therefore produces less secondary particulates during the various handling and / or use of compacted materials in industrial processes. .. Such pulverization rates are satisfactory in the context of the present invention.

Whether assessing their resistance to mechanical compression or their pulverization rate, the consolidated material is after step d), where the consolidated material is oven-dried immediately after demolding the consolidated material. , Or after a heating process that simulates the introduction of them at high temperatures in an industrial process, the heating itself is a step d) in which the compacted material is oven-dried. Will be carried out after.

If the consolidated materials were tested at room temperature immediately after oven drying in step d) without further heat treatment, those tests are referred to as "cold" tests.

Conversely, if they are tested after heat treatment, those tests are called "hot" tests. In practice, the heat treatment of the consolidation material is divided into three phases: the first phase raises the temperature at 50 ° C / hour, the second phase sets the temperature (here 700 ° C or 900). “Plateau” for 1 hour and 45 minutes (where ° C is selected), and in the third phase, temperature reduction at 50 ° C / hour. After they have returned to room temperature, the consolidation material is tested.

II. 1 Mechanical compressive strength Mechanical compressive strength (unit, megapascal (MPa)) is evaluated using a so-called 3R press, which is typical in the evaluation of cement-based materials, according to the protocol described in the EN 196 standard. The press is commercially available under the name Ibertest®.

In practice, the consolidation material is placed in the center on a fixed plate, under a movable side punch tailored to apply a predetermined compressive force to the consolidation material.

The punch is first brought into contact with the material and then a compressive force is applied to the consolidation material in the same direction as it was applied during the production of the consolidation material. A compressive force is applied until the material is destroyed. The compressive strength (Rc) of the consolidated material actually corresponds to the stress applied when the material was destroyed. The increase in compression is on the order of 2400 Newtons / sec and the maximum force that can be applied is 200 Kilonewtons. This test is performed on at least 3 samples. It is then averaged and regarded as the mechanical compressive strength of the material considered.

II. 2 Powdering rate To measure the powdering rate, two tests are possible, depending on the size of the consolidated material obtained: a concrete mixer for the consolidated material of large size (more than 10 cm). Testing; and jar testing for small size substances.

The concrete mixer test is based on the ASTM "Los Angeles" test for assessing the grinding of aggregates.

In practice, five large consolidation materials are weighed and then placed in a 174 liter steel concrete mixer (model RS180, LESCHA) (60 cm diameter, 24 rpm). Place the consolidation material in a rotating concrete mixer for 30 minutes.

Next, the contents of the concrete mixer are separated by 40 mm, and the fine particles that have passed through the sieve are regarded as secondary fine particles. Large debris that has not passed through the sieve is weighed and compared to the initial mass fed into the concrete mixer.

More specifically, the pulverization rate T, that is, the generation rate of secondary fine particles, can be calculated as the ratio of the difference between the initial mass and the final mass of the consolidated substance to the initial mass, which is expressed by the following equation. You can also:
T = [initial mass-final mass] / initial mass

The jar test is used to assess the generation of secondary particulates in the consolidated material obtained using a miniature device.

Similarly, some of the consolidation materials, for example 5 blocks, are weighed and a 6 liter cylindrical jar (15 cm in diameter, 15 cm in height, inner surface is Linatex (extremely smooth rubbery material). ) Covered). The jar is rotated at 45 rpm for 30 minutes (1350 rpm in total) to evaluate the mass loss of the consolidated material.

As in the case of the concrete mixer test, the pulverization rate T, that is, the rate of generation of secondary fine particles, can then be calculated according to the following equation:
T = [initial mass-final mass] / initial mass

III. Manufactured Consolidation Substances Various examples of consolidation substances were produced from various crude raw material materials and water-hard binders.

III. 1 Raw material The crude raw materials used in the various examples are red bauxite and white bauxite. It is also possible to use limestone, carbon black, and rock wool.

The carbon blacks that can be used are, for example, those commercially available under the name of Thermax® N990. It consists of 99.1% by weight amorphous carbon black.

The rock wool that can be used is, for example, one commercially available under the name Le Flocon 2®-Rockwool.

Alternatively, 99.5% by weight of pure alumina (hereinafter referred to as "test alumina") can be used.

Table II shows the chemical composition of other crude materials used or available, namely red bauxite, white bauxite, and limestone, as mass percent (ie, mass relative to total mass of crude material).

Table III below shows the particle size and density of some dried (ie, oven-dried at 110 ° C. for 24 hours) crude material.

III. 2 Water-hard binder The water-hard binder used in various examples is Cement Fondu (registered trademark) and Secar (registered trademark) 51 cement. It is also possible to use Portland cement.

Usable Portland cement is, for example, one commercially available under the trade name of CEM I 52.5R MILKE PREMIUM.

Tables IV and V below show the chemical and mineralogical compositions of Cement Fondu® Cement and Secar® 51 Cement, respectively, in mass percent (based on the total mass of the cement in question). ).

FIG. 2 shows the particle size distribution of two batches of the crude material particles used, namely the white bauxite particles known as "ABP" and the red bauxite particles known as "ELMIN". Furthermore, the particle size distributions of two batches of fine particles of the cement used, namely Cement Fondu (registered trademark) cement and Secar (registered trademark) 51 cement, are shown. In FIG. 2, the y-axis represents a volume percentage of particles having a diameter equal to the dimensions shown on the x-axis, relative to the total volume of the particle set for each batch of interest.

The table VI below shows the particle size distribution of Cement Fondu® and Secar® 51 cement.

III. 3 Consolidation substance Example 1
In Example 1, the compaction strength and pulverization rate of the consolidated material of the red bauxite particles obtained by the process of the present invention (Example 1a) are measured by those of the natural blocks of red bauxite (Example 1ref). And compared with those of the consolidated material of red bauxite particles obtained according to a process not according to the present invention (Example 1b). Here, the process not according to the present invention is different from the process according to the present invention in that vibration is not used.

Step a):
The dry compositions used to produce the compacted material in Examples 1a and 1b include 85% "ELMIN" type red bauxite and 15% by mass relative to the total mass of the dry composition. Includes Cement Fondu® cement, the properties of which are III. Item 1 and III. It is described in Section 2.

In practice, all red bauxite particles are categorized using a 560 micrometer sieve, the particle size distribution of which is equal to the first reference diameter d90, which is equal to 520 micrometers, and 5.6 micrometers. It has a reference diameter d10 of 2 and a median diameter d50 equal to 255 micrometers.

Step b):
The dry composition is mixed with 10% water by mass relative to the total mass of the dry composition. To do this, the water-mixed composition is mixed by hand for 1 minute.

Step c):
In Example 1a, the water-mixed composition is then introduced into the mold described at Point I (Manufacturing Equipment), which can be processed by a miniature equipment that uses vibration.

In Example 1b, the water-mixed composition is processed by a miniature device that does not use any vibration.

Table VII below summarizes the conditions for obtaining the consolidated materials of Examples 1a and 1b.

Table VIII below summarizes the results obtained for the compacted materials in Examples 1a and 1b, as well as the blocks of natural red bauxite (Example 1ref).

The pulverization rate was measured by a jar test for the consolidated material in Examples 1a and 1b and a concrete mixer test for a block of natural bauxite.

According to the results obtained, the process according to the present invention has a higher mechanical compressive strength than the mechanical compressive strength of the consolidated material (Example 1b) obtained by the process not according to the present invention in the cold test. It has become possible to obtain a compacted substance (Example 1a). Therefore, by vibrating the composition before and during the application of compressive stress, the mechanical compression strength in the cold test is improved (in this case, the mechanical compression in the cold test). 23% improvement in strength).

In addition, the consolidated material obtained by the process of the present invention (Example 1a) has a much lower pulverization rate than the natural red bauxite block (Example 1ref) in both hot and cold tests. have. In fact, thanks to the process in the present invention, the compacted material is about 2.5 times smaller than the natural block in the cold test, and about 2.5 times smaller than the natural block in the hot test. Only one-sixth of the secondary particles are produced.

Example 2
In Example 2, the principles of Example 1 are applied, but with the consolidation of white bauxite particles and the natural blocks of white bauxite.

Therefore, in Example 2, the compaction strength and pulverization rate of the consolidated substance of the white bauxite particles obtained by the process of the present invention (Examples 2a and 2c) are adjusted to those of the natural white bauxite block (implementation). Example 2ref), as well as those of the consolidation of white bauxite particles obtained by a process not according to the invention (Examples 2b, 2d). Here, as in the case of the first embodiment, the process not according to the present invention is different from the process according to the present invention in that vibration is not used.

Step a):
The dry compositions used to make the compacted material in Examples 2a and 2b include 85% white bauxite and 15% Cement® 51 by mass relative to the total mass of the dry composition. Cement is included, but the properties of each of them are III. Item 1 and III. It is described in Section 2.

The dry compositions used to prepare the compacted material in Examples 2c and 2d were 50% white bauxite and 35% mass purity 99.5%, based on the total mass of the dry composition. Test alumina and 15% Secar® 51 cement are included, the properties of which are III. Item 1 and III. It is described in Section 2.

Step b):
The dry compositions of Examples 2a, 2b, 2c, and 2d are mixed with 10% water by mass relative to the total mass of the corresponding dry composition. They are mixed by hand for 1 minute.

Step c):
In Examples 2a and 2c, the water-mixed composition is processed by a miniature device, which uses vibrations with a frequency of 60 Hz and an amplitude of 0.35 mm, and a compressive stress of 11 MPa.

In Examples 2b and 2d, the water-mixed composition is processed by a miniature device, which uses a compressive stress of 11 MPa but no vibration.

Table IX below summarizes the conditions for obtaining a consolidated substance in Examples 2a and 2b.

Table X below summarizes the results obtained with the compacted materials in Examples 2a, 2b, 2c and 2d, as well as the blocks of natural white bauxite (Example 2ref). The pulverization rate was measured by a jar test for the consolidated material in Examples 2a and 2b and a concrete mixer test for a block of natural bauxite.

Therefore, as seen in Example 1, the consolidation material obtained by the process of the present invention (Example 2a) was obtained by a vibration-free process not according to the present invention (Example 2a). Compared with 2b), the mechanical compression strength in the cold test is improved.

As in the case of Example 1, the pulverization rate of the consolidated substance (Example 2a) obtained by the process of the present invention was a block of natural white bauxite (Example 2ref) in both the hot test and the cold test. ) Is much lower than that.

Finally, comparing the results of Examples 1a and 2a, the process in the present invention consolidates using different crude material, in this case both white bauxite particles and red bauxite particles. It can be seen that it is possible to obtain a new substance. In either case, in both hot and cold tests, the mechanical compressive strength is well above 10 MPa and the pulverization rate is less than 10%.

Example 3
In Example 3, the substances compacted by the process of the present invention (Examples 1a and 2a) and the substances compacted under extremely high compressive stress but without vibration (Examples 3a, 3b, and 3d). ) And the compaction strength and the pulverization rate were compared.

The dry compositions used to make the compacted material in Examples 3a and 3b include 85% red bauxite and 15% Cement Fondu®, based on the total mass of the dry composition. ) Or Secar® 51 cement, the properties of which are III. Item 1 and III. It is described in Section 2. In practice, the red bauxite particle set is categorized using a 4 mm sieve and its particle size distribution is equal to 3.5 mm, equal to first reference diameter d90, equal to 315 micrometers, second. It has a reference diameter d10 and a median diameter d50 equal to 2 millimeters.

The dry compositions of Examples 3a and 3b are mixed with 7% water by mass relative to the total mass of the dry composition.

The dry composition used to make the compacted material in Example 3d consists of 85% white bauxite and 15% Cement Fondu®, the properties of which are III. Item 1 and III. It is described in Section 2. In this case, the dry composition is mixed with 12% water by mass based on the total mass of the dry composition.

In Examples 3a, 3b, and 3d, the composition is then introduced into a cylindrical mold 39 mm in diameter and 80 mm in height, regardless of the water-mixed composition formed. Then, a compressive stress on the order of 40 MPa is applied by a hydraulic press commercially available under the name of Zwick (registered trademark).

In Example 3c, the compressive strength of the material without the water-hard binder, with compaction under extremely high compressive stress, and without vibration was also evaluated.

Table XI below summarizes the conditions for obtaining the consolidated materials of Examples 3a, 3b, 3c, and 3d.

Table XII below summarizes the results obtained with the consolidated materials in Examples 3a, 3b, 3c, and 1a for direct comparison. For the consolidated substances in Examples 3a, 3b and 3d, the pulverization rate was measured by a jar test.

Table XIII below summarizes the results obtained with the consolidated materials in Examples 3d and 2a for direct comparison.

The results in Tables XII and XIII show that during production, a very high compressive stress is applied to the material, but without vibration (Examples 3a, 3b, and 3d), the compressive strength is high compressive stress and vibration. It is shown that it is lower than when both are applied (Examples 1a and 2a). Therefore, even if an extremely high compressive stress is applied to a substance during production, it is insufficient to improve its mechanical compressive strength. It is actually a combination of high compressive stress application and vibration, the vibration being carried out both before and during the compression, thereby consolidating with satisfactory mechanical compression strength. It becomes possible to generate a chemical substance.

In addition, the results in Tables XII and XIII show that when a high compressive stress is applied to a material in combination with vibration (Examples 1a and 2a), only a high compressive stress is applied to the material and no vibration is applied (Examples 1a and 2a). It is shown that the pulverization in the hot test and the cold test is remarkably reduced as compared with 3a, 3b, and 3d). Even if a very high compressive stress is applied to the material during production, its pulverization rate does not drop below that of the natural block. It is actually a combination of high compressive stress application and vibration, the vibration being carried out both before and during the compression, thereby consolidating with a satisfactory pulverization rate. It is possible to generate a substance.

Finally, Example 3c shows that the water-hard binder plays a crucial role in the strength of the compacted material. In other words, the fine particles of the crude raw material do not have sufficient cohesive force to mechanically hold each other even when an extremely high compressive stress is applied. Therefore, it is necessary to use a water-hard binder in order to mutually agglomerate the fine particles of the crude raw material.

Example 4
In Example 4, the material compacted by the process of the present invention (Examples 1a and 2a) and the material compacted by the process containing low compressive stress and vibration (Examples 4a and 4b) are compressed. The strength and pulverization rate were compared.

In Examples 4a and 4b, the dry composition used to prepare the compacted material includes 85% red bauxite (Example 4a) or white bauxite (Example 4a) or white bauxite (Example 4a) by mass based on the total mass of the dry composition. Examples 4b) and 15% Cement Fondu® (Example 4a) or Secar® 51 (Example 4b) cements are included, the properties of which are III. Item 1 and III. It is described in Section 2.

In these two Examples 4a and 4b, the dry composition is mixed with 4% water by mass relative to the total mass of the dry composition. The composition so mixed is introduced into a large, oiled steel mold. The mold in this case has a square cross section of 100 mm on each side. Place the mold under a large press with a shaking table. In practice, the water-mixed composition introduced into the mold is vibrated before and during the application of compressive stress.

The production conditions for the substances to be consolidated in the laboratory equipment are summarized in Table XIV below.

The consolidated materials of Examples 4a and 4b thus obtained are manually demolded and then placed in a drying oven at 20 ° C. and 90% relative humidity for 24 hours.

Table XV below summarizes the results obtained for the compacted materials of Examples 4a and 1a on the one hand and Examples 4b and 2a on the other. The pulverization rate was measured for the consolidated substances in Examples 4a and 4b according to the concrete mixer test method.

Comparing the results obtained with the compacted materials of Examples 4a and 1a on the one hand and Examples 4b and 2a on the other hand, when the material was obtained by the process of the present invention, the material had low compressive stress and It shows that the mechanical compressive strength is improved in both cold and hot tests compared to when obtained by existing processes involving vibration. Specifically, in Example 4a and Example 1a, the mechanical compression strength is tripled.

Therefore, when vibration is applied both before and during the application of high compressive stress and the application of compressive stress, consolidation with improved compressive strength compared to the consolidation material obtained by existing processes. The substance is obtained.

The consolidation rate of the consolidated material obtained by the process of the present invention is also compared with the powder rate of the natural block, and the compacted material powder obtained by the existing process including low compressive stress and vibration. It is low compared to the conversion rate.

Therefore, it is clear from all the descriptions and examples that the combination of vibration and the application of high compressive stresses yields a consolidated material with satisfactory compressive strength and pulverization rate.

Furthermore, it has also been shown in the present invention that the combination of compressive stress and the application of vibration increases the density of the consolidation material, which reduces the porosity and in the consolidation material. It suggests a homogeneous distribution of the constituents of the composition (no component bias, sedimentation, or heterogeneous distribution).

Example 5
In Example 5, a consolidated bilayer material of red bauxite particles and limestone is obtained by the process according to the invention (Example 5a).

The dry composition used to prepare the compacted material in Example 5a has a mass based on the total mass of the dry composition, and 85% red bauxite (“EB”) in the first layer. Type) and 15% Ciment Fondue Cement, and in the second layer 95% Limestone CaCO ₃ and 5% Ciment Fondue® Cement, the properties of each of which are: III. Item 1 and III. It is described in Section 2.

In this Example 5a, the dry composition for the first layer is mixed with 7% water by mass relative to the total mass of the dry composition. The dry composition for the second layer is mixed with 5% water by mass relative to the total mass of the dry composition. The composition for the first layer thus mixed is introduced into a large, oiled steel mold. The mold in this case has a square cross section of 100 mm on each side. The composition for the second layer thus mixed is then introduced onto the composition for the first layer in the mold. Place the mold under a large press with a shaking table. In practice, the two water-mixed compositions introduced into the mold are vibrated before and during the application of compressive stress.

The conditions for producing the consolidated material in the laboratory equipment are summarized in Table XVI below.

Table XVII below summarizes the results obtained with the consolidated bilayer material in Example 5a.

The pulverization rate was measured by the jar test for the consolidated material in Example 5a.

In this way, it is shown that the process in the present invention makes it possible to obtain a consolidated two-layer material whose mechanical compression strength is sufficiently satisfactory.

Example 6
In Example 6, the compressive intensities and densities of the red bauxite particle compaction substances obtained by the process of the present invention were compared at different compression values (Examples 6a-6f).

The production conditions for the materials to be consolidated in the pilot device are summarized in Table XVIII below.

Table XIX below summarizes the results obtained for the consolidated materials in Examples 6a-6f.

In this way, if it is higher than 2 MPa, the mechanical compressive strength of the process in the present invention is extremely satisfactory in both the cold test and the hot test, regardless of the value of the compressive stress. It became clear that it is possible to obtain.

Example 7
In Example 7, the compressive strength and density of the consolidated material of the red bauxite particles obtained by the process of the present invention at different binder ratios (Examples 7a, 7b) was compared with Example 6b.

The production conditions for the materials to be consolidated in the pilot device are summarized in Table XX below.

Table XXI below summarizes the results obtained for the consolidated materials in Examples 7a and 7b and compares them with Example 6b.

Example 8 (core)
In Example 8, the compressive strength and pulverization rate of the "core" material (also referred to as the "core-shell" compaction material) of the red bauxite particles, which has cores of different composition, is the process according to the invention (implementation). Obtained by Examples 8a and 8b).

The dry compositions used to make the compacted material in Example 8a have a mass relative to the total mass of the dry composition, respectively, in a mixed composition known as the outer layer. , 85% Red Bauxite EB and 15% Cement Fondu® Cement, and in the core 100% Red Bauxite EB, the properties of which are III. Item 1 and III. It is described in Section 2.

In this Example 8a, the dry composition for the outer layer is mixed with 7% water by mass relative to the total mass of the dry composition. The dry composition for the core is mixed with 5% water by mass relative to the total mass of the dry composition.

The dry compositions used to make the compacted material in Example 8b have a mass relative to the total mass of the dry composition, respectively, with 85% EB red bauxite and 15% in the outer layer. Cement Fondu Cement, and the core contains 95% EB red bauxite and 5% Cement Fondo Cement, the properties of which are III. Item 1 and III. It is described in Section 2.

In this Example 8b, the dry composition for the outer layer is mixed with 7% water by mass relative to the total mass of the dry composition. The dry composition for the core is mixed with 7% water by mass relative to the total mass of the dry composition.

The composition for the core layer thus mixed is introduced into an oiled, steel, cylindrical mold having a diameter of 30 mm. Place the mold under a large press with a shaking table. The core is then pressed and at the same time vibrated according to the process in the present invention.

A 16 g mixed outer layer was then introduced into the bottom of a second cylindrical steel mold 40 mm in diameter, and then a preformed "core" cylinder was placed in the center thereof and the rest of the outer layer composition. Cover with one.

The production conditions for the materials to be consolidated in the "miniature" laboratory equipment are summarized in Table XXII below.

Table XXIII below summarizes the results obtained with the consolidated materials in Examples 8a and 8b.

Therefore, the process in the present invention makes it possible to obtain a "core-shell" type consolidation material with satisfactory mechanical compression strength.

Claims (19)

It ’s a way to get a consolidation substance,
a) On the one hand, a set of crude material particles whose particle size distribution is characterized by a first reference diameter d90 of 50 millimeters or less and a second reference diameter d10 of 0.08 micrometer or more, and the other. Then, the dry composition is formed by mixing 1% to 50% of a water-hard binder with a mass based on the total mass of the dry composition.
b) The dry composition formed in step a) is mixed with 1% to 35% water at a mass based on the total mass of the dry composition to form a mixed composition.
c) The mixed composition obtained in step b) is vibrated at a frequency between 20 hertz and 80 hertz and an amplitude of 0.3 mm or more, and then combined with the vibration to obtain the above. Compressive stress is applied to the mixed composition and
The value of the applied compressive stress is 2 megapascals or more.
Method. The mixed composition obtained at the end of step b) is used to form a first layer of material.
In step p1) prior to step c), steps a) and b) are repeated to form at least one other mixed composition.
In step p2), the other mixed composition obtained in step p1) is placed on the first layer formed at the end of step b) and at least two of the mixed compositions are placed. Form a stack of two layers,
In step c), the stack formed in step p2) is vibrated at a frequency between 20 hertz and 80 hertz and an amplitude of 0.3 millimeters or more, and then combined with the vibration to obtain the said. Applying compressive stress to the stack,
The method according to claim 1. In step n1), a core of a crude raw material is provided, and the core has a mechanical strength of 0.1 megapascal (MPa) or more.
In step n2) performed prior to step c), the core is completely encapsulated in the mixed composition obtained in step b).
In step c), the assembly containing the at least one mixed composition and the enclosed core is vibrated at a frequency between 20 Hz and 80 Hz and an amplitude of 0.3 mm or more. Then, in combination with the vibration, the compressive stress is applied to the aggregate.
The method according to claim 1. In step n1), a core of a crude raw material is provided, and the core has a mechanical strength of 0.1 megapascal (MPa) or more.
In step n2') performed prior to step c), the core is mixed in and / or the other mixture obtained in step p1) in the mixed composition obtained in step b). Completely encapsulated in at least one of the compositions
In step c), the assembly containing the at least one mixed composition and the enclosed core is vibrated at a frequency between 20 Hz and 80 Hz and an amplitude of 0.3 mm or more. Then, in combination with the vibration, the compressive stress is applied to the aggregate.
The method according to claim 2. The method according to claim 3 or 4, wherein the core obtained in step n1) is a consolidation substance formed by consolidation of another set of crude raw material particles. The method according to any one of claims 3 to 5, wherein the core is obtained by the method according to claim 1 or 2. A method for obtaining a multi-layer consolidation material,
The first layer,
a) On the one hand, a set of crude material particles whose particle size distribution is characterized by a first reference diameter d90 of 50 millimeters or less and a second reference diameter d10 of 0.08 micrometer or more, and the other. Then, the dry composition is formed by mixing 1% to 50% of a water-hard binder with a mass based on the total mass of the dry composition.
b) The dry composition formed in step a) is mixed with 1% to 35% water at a mass based on the total mass of the dry composition to form a mixed composition.
c') The mixed composition of step b) is vibrated at a frequency between 20 and 80 hertz and an amplitude of 0.3 millimeters or more, then combined with the vibration and mixed. Applying compressive stress to the composition,
Made according to the process,
Moreover, in each subsequent layer, another mixed composition is prepared by repeating steps a) and b), but the other mixed composition is placed on the previous layer. Placed, the assembly formed by the previous layer and the other mixed composition is vibrated and compressive stress is applied to the assembly.
The value of the compressive stress applied to prepare at least the last layer of the multilayer consolidation material is 2 megapascals or more.
Method. The method according to any one of claims 1 to 7, wherein the vibration performed in combination with the application of the compressive stress is made anharmonic. The method according to any one of claims 1 to 8, wherein the vibration has an amplitude between 0.3 mm and 5 mm in accordance with the direction of compression. In order to obtain the consolidation material, a step following step c) is further provided, in which the consolidation material is placed in a drying oven relative to a predetermined temperature and relative humidity threshold or higher. The method according to any one of claims 1 to 9, which is left in a humidity for at least 24 hours. The crude material particles in each set of particles may be obtained during ore mining or in the manufacturing process, red bauxite, white bauxite, alumina, limestone, lime, carbon, carbon graphite, carbon black, rock wool, Any of claims 1-10, which is a mineral particle selected from glass wool, carbonate, metallurgical eluent, manganese powder or a derivative thereof, metal ore or a mixture of ores, particularly metal oxide or iron ore. The method according to item 1. For at least one set of crude material particles, the first reference diameter d90 associated with the particle size distribution of the set of crude material particles is less than 20 millimeters and the second reference diameter d90 associated with the particle size distribution. The method according to any one of claims 1 to 11, wherein the reference diameter d10 is 0.1 micrometer or more. The water-hard binder is selected from Portland cement, calcium aluminate cement, sulfoluminate cement, cement mixed with fly ash, cement mixed with blast furnace slag, cement mixed with pozzolan, or a mixture thereof. Item 2. The method according to any one of Items 1 to 12. The method according to any one of claims 1 to 13, wherein in step a), the water-hard binder contains calcium aluminates cement having a C / A molar ratio between 0.1 and 3. In step a), claims 1-14, wherein the water-hard binder comprises a set of water-hard binder particles having a particle size distribution of 100 micrometers or less, characterized by a first reference diameter d90. The method according to any one of the above. A consolidation substance, which is a consolidation substance and contains crude raw material particles agglomerated by a water-hard binder, which is obtained by the method according to any one of claims 1 to 15. The compacted substance according to claim 16, which has a mechanical compression strength of 3 megapascals or more and a pulverization rate of 15% or less. At least two layers of a crude material which is a multi-layer consolidation substance obtained by the method according to any one of claims 2 or 4 to 15 and is mutually inactive until the temperature rises to a predetermined threshold temperature. Multilayer consolidation material, including a stack of layers of. A multi-layer compaction substance obtained by the method according to any one of claims 3 to 6, which contains a core encapsulated in at least one outer layer, and the crude raw material of the core is previously contained. A multi-layer compaction material that is inactive with the crude material of the outer layer of at least one layer in which it is encapsulated until it reaches a predetermined threshold temperature.